Most processes that employ the use of chemicals have the potential to cause harm to the environment. Indeed, the recognition that many of the chemical processes that are essential to the development of many modem conveniences—such as pharmaceuticals, consumer products, or transportation or communication devices—may have a harmful effect on the environment, has lead to the rise of the technological field known as “Green Chemistry.” The mandate of Green Chemistry is to design, develop, and implement chemical processes and products that reduce or eliminate substances hazardous to human health and the environment. So critical is the achievement of Green Chemistry's mandate that the National Academy of Sciences established a Green Chemistry Awards program in 1995. The Green Chemistry Awards represent a competitive effort to promote chemical products and manufacturing processes that prevent pollution yet are economically viable.
One goal of Green Chemistry is to minimize or eliminate the use of solvents that are incompatible with the environment. This has lead to the use of water or other environmentally compatible solvents in some chemical processes, and to the search for substrates, reagents and reactions that are compatible with water. We identified mucohalic acid 1 (mucochloric acid (2,3-dichloro-4-oxo-2-butenoic acid) and mucobromic acid 1 (2,3-dibromo-4-oxo-2-butenoic acid), as promising candidates for Green Chemistry processing.

Mucochloric acid and mucobromic acid are commercially available and inexpensive starting materials. Both molecules are characterized by the presence of a carbon-carbon double bond with Z configuration, two halogen atoms, and two carbonyl groups. This high degree of functionality makes mucochloric and mucobromic acid particularly useful building blocks for the synthesis of a variety of biologically active heterocycles, such as substituted 1,5-dihydropyrrol-2-ones, pyrrolidines, and γ-lactams, as well as others.
Despite its great synthetic potential, however, mucohalic acid has not been commonly employed in conventional organic synthesis as a C-4 building block, let alone in “Green” organic synthesis. Presumably, this is because of the many reactive sites in the molecule, its poor stability under basic conditions, and the perception among those of ordinary skill in the art of the difficulties associated with the selective manipulation of the halogen atoms in the presence of the other functionality.
As a result, there is a need for methods or processes that allow for the selective manipulation of the functional groups present in mucolialic acid, in an environmentally compatible “Green solvent”, at mild pH, atmospheric pressure, and at room temperature or lower.